请问，什么情况下在一个句子中出现两个“了”？

“口”这个量词现在还用吗？ 来自中国的朋友们，我刚在ＩＴＡＬＫＩ上看到有人这样写： very good. but try to say 几个人but not 几口人。几口人is a very old fashion expression and not suit for you being a young lady. historically, Chinese people was very poor in a period time. so people cared lot about food. you may know that 口means mouth which is used for eating food. So people cared about how many mouths were there demanding food. so some elders just counted mouths instead of familiy members. And nowadays young adolescents barely use 几口人 especially in the south China. 请问，现在真的不怎么用“口”这个量词吗？